1. Field of the Invention
Among other things, the present invention is related to a lumbosacral or intervertebral implant. The doughnut-like implant includes an asymmetrical opening surrounded by a series of load bearing sections of distinct curvatures. Some preferred embodiments are provided with a forwardly projecting arm and plate combination to assist with stabilization of the doughnut-like implant. Other preferred embodiments of the doughnut-like implant can include tapered lateral sections of distinct curvatures.
2. Description of the Previous Art
1) U.S. Pat. No. 6,425,920-Hamada enables a spinal fusion implant. In part, Column 38 of Hamada reads, “Continuing with a description of the implant 701, FIG. 59 is a sectional view looking toward anterior end “A”. Opposite the left side 713, a right side 715 is now seen. The implant 701 has a generally toroidal extent shaped mass of bone tissue 717. The central opening 707 may be packed with a material seen as material 718 which may be one of several combinations of materials and structures. Material 718 is also shown within the slot 709.”
Among other things, the '920 patent does not teach or suggest the use of an irregular central opening, an aperture located proximate the inferior edge for receiving a fastener, first and second annular-like sides distinct from the anterior and posterior curvatures, a posterior curvature protruding forward and toward the reference vertical axis, where the posterior curvature is angled more acutely than the anterior curvature, a forwardly extending arm attached to the superior edge of the anterior curvature and a plate comprising an aperture connected to the forwardly extending arm.
2) U.S. Pat. No. 6,146,421-Gordon enables a multiple axis intervertebral prosthesis. In part, Columns 3 and 4 of the '421 patent read, “The present invention relates to a variable axis intervertebral disk prosthesis (see FIG. 1). The prosthesis has two components (see FIG. 4), male 10 and female 12, and is for implantation between two adjacent vertebrae in place of a spinal disk. Attachment to the adjacent vertebrae is accomplished at least in part by means of an attachment element, preferably mechanical attachment elements such as screws 14 which pass through a flange 16. Alternatives to screws such as pegs or posts are acceptable means for attaching the components to the vertebrae, as long as they are strong enough to handle the compressive forces exerted on it, and are a reliable form of fixation. Bone cement may also be used for attachment to the adjacent vertebrae, either in place of or in addition to mechanical attachment elements. The preferred length and diameter of the mechanical attachment elements is determined by the surgeon depending on the size of the patient and the location in the spine where the disk is being replaced. If using screws, they may be inserted straight into the vertebrae or at an angle. In one preferred embodiment, the screws are inserted straight into the vertebrae (see FIG. 1). In another preferred embodiment, a screw is inserted into the vertebra at an angle (see FIG. 5).
The male portion 10 of the prosthesis comprises a cylindrical support plate 18, which in a preferred embodiment is wedge shaped. The wedge shaped plate 18 allows for building lordosis into the prosthesis. The wedge shaped plate 18 has one rough-faced surface 20 that would mate with a vertebra. In a preferred embodiment, the male component 10 is the upper component and the rough surface 20 is on the upper surface 80 of the wedge shaped plate 18 (see FIG. 4). The rough surface allows for another means of fixation to a vertebra, as an alternative to or in addition to the mechanical attachment elements. A presently preferred embodiment has both attachment elements, such as screws 14, and a rough surface 20 to provide for the most stable fixation.
Extending vertically from the edge of the upper surface 20 of the support plate is at least one flange 16. In a preferred embodiment, the male component is the upper component and the flange extends upward from the thick side of the wedge shaped plate 28 (see FIG. 1). The flange is a mounting tab that can receive the attachment elements, such as screws 14. The screws are guided through openings 22 in the flange in order to attach the male portion 10 to a vertebra. There are at least two openings 22 through which (at least two) attachment elements can pass. In a preferred embodiment, the openings 22 in the flange 16 are figure eight shaped openings 34 (see FIG. 3). The figure eight shaped opening aids in facilitating different screw heights. Different heights are chosen by the surgeon depending on what best fits each particular patient. The opening 22 can also be circular, or oval in shape.”
Among other things, the '421 patent does not teach or suggest the use of doughnut-like implant with an irregular central opening, having a reference vertical axis, first and second annular-like sides distinct from the anterior and posterior curvatures, a posterior curvature protruding forward and toward the reference central vertical axis, where the posterior curvature is angled more acutely than the anterior curvature and a plate comprising an aperture, where the plate is connected with the forwardly extending arm, and where the plate extends upward from the forwardly extending arm and is generally parallel the reference axis.
3) U.S. Pat. No. 6,228,118-Gordon enables a multiple axis intervertebral prosthesis. The '118 patent has identical disclosure as the '421 patent's disclosure set forth above. Therefore, the '118 patent does not teach or suggest the use of doughnut-like implant with an irregular central opening, having a reference vertical axis, first and second annular-like sides distinct from the anterior and posterior curvatures, a posterior curvature protruding forward and toward the reference central vertical axis, where the posterior curvature is angled more acutely than the anterior curvature and a plate comprising an aperture, where the plate is connected with the forwardly extending arm, and where the plate extends upward from the forwardly extending arm and is generally parallel the reference axis.
4) U.S. Pat. No. 6,533,818-Weber, et al. enables an artificial spinal disc. In part, Column 4 of the '818 patent reads, “FIG. 1 shows a perspective view of one embodiment of the artificial spinal disc implant. The implant 10 is designed to approximate the shape and size of natural intervertebral discs. It has a planar top 12 and bottom 14 that bond to the vertebral bone when implanted in the vertebral spine. The implant is comprised of three distinct layers including a central layer 16.”
Among other things, the '818 patent does not teach or suggest the use of doughnut-like implant with an irregular central opening, having a reference vertical axis, a posterior curvature protruding forward and toward the reference vertical axis, where the posterior curvature is angled more acutely than the anterior curvature, a first annular-like side distinct from the anterior and posterior curvatures and connected with the anterior solid curvature and the posterior curvature, where the first annular-like side includes an upper boundary and a lower boundary, and where the upper boundary and the lower boundary taper toward each other as the first annular-like side traverses from the anterior curvature to the posterior curvature, a second annular-like side distinct from the anterior and posterior curvatures and connected with the anterior curvature and the posterior curvature, where the second annular-like side includes an upper boundary and a lower boundary, and where the upper boundary and the lower boundary taper toward each other as the second annular-like side traverses from the anterior curvature to the posterior curvature, a forwardly extending arm attached to the superior edge of the anterior curvature, and a plate comprising an aperture, where the plate is connected with the forwardly extending arm, and where the plate extends upward from the forwardly extending arm and is generally parallel the reference axis.
5) U.S. Pat. No. 7,018,412-Ferreira, et al. enables an allograft spinal implant. In part, Column 5 of the '412 patent reads, “With reference to FIG. 5, a simplified lateral side view of an allograft spinal implant constructed according to the teachings of a second preferred embodiment of the present invention is generally identified at reference numeral 30. As with the first preferred embodiment, the implant is particularly intended for cervical spine applications. The implant 30 of the second preferred embodiment will be understood to be identical to the spinal implant 10 of the first preferred embodiment with the exception that superior and inferior end faces 32 and 34 of the implant 30 are not parallel to one another but relatively angled to accommodate natural spinal lordosis. In one exemplary application, the superior and inferior end faces 32 and 34 are angled from one another at approximately 5°. However, it is anticipated that the lordodic angle may fall within the range of 0° to approximately 10° or greater.
The implant 30 includes an anterior height h 1, a posterior height h 2, an outer diameter or depth D, and a through hole 36 having a diameter d. As with the spinal implant 10 of the first preferred embodiment, the through hole diameter d of the implant 30 preferably ranges from 0 mm to approximately 6 mm and the overall diameter or depth D preferably ranges from approximately 8 mm to approximately 15 mm. In these applications, the anterior height preferably ranges from approximately 8 mm to approximately 14 mm and the posterior height ranges from approximately 5 mm to approximately 11 mm.”
In part, Column 5 of the '412 patent reads, “With reference to FIGS. 25-28, various stages of the implant 180 during a manufacturing process are illustrated. As shown in FIG. 25, a rough implant 121 is harvested from a transverse section of cortical bone. The rough implant 121 includes a through hole 122 that is naturally formed in the bone by the intramedullary canal.”
In part, Column 8 of the '412 patent reads, “With to FIGS. 45-48, an allograft spinal implant constructed in accordance with the teachings of a twelfth preferred embodiment of the present invention is illustrated and generally identified at reference character 250. The implant 250 is particularly intended for anterior lumbar interbody fusion applications. The long axis of the donor bone is indicated by arrow C. The implant 250 defines a generally central aperture 252. As with various prior embodiments of the present invention, the implant 250 is formed to include a plurality of concentric-arc ridges 254 on both the inferior and superior surfaces. In the embodiment illustrated, the superior and inferior end faces are angled from one another at approximately 6°. However, it is anticipated that the lordodic angle may fall within the range of 0° to approximately 6° or greater than 6°.”
Among other things, the '412 patent does not teach or suggest the use of a biocompatible metallic or plastic doughnut-like implant, a forwardly extending arm attached to the superior edge of the anterior curvature and a plate comprising an aperture, where the plate is connected with the forwardly extending arm, and where the plate extends upward from the forwardly extending arm and is generally parallel the reference axis.
6) U.S. Pat. No. 7,025,787-Bryan, et al. enables an implantable joint prosthesis and associated instrumentation. In part, Columns 11 and 12 of the '787 patent read, “Preferably, shells 20, 40 are cup-like so as to include an outer convex surface 23 and an inner concave surface 21, 41. The outer surfaces 23 can be coated with a nonspherical sintered bead coating 22, 42, or with some other coating that will promote bony ingrowth. The inner surfaces 21, 41 (shown in FIG. 6) are preferably very smooth, and may be machined or polished.
The shells 20, 40 include a number of geometric features that as described in further detail below cooperate with other components of the devices. Specifically, these features include a central retaining post 27, 47, an outer circumferential groove 82, 84, and a radial stop or an extension 86, 88. The central retaining post 27, 47 extends axially from inner surfaces 21, 41. In addition, each shell 20, 40 includes an edge 73, 74, respectively. The outer circumferential grooves 82, 84 extend into the edges 73, 74 of the shells 20, 40. As seen best in FIG. 6, the radial stops or extensions 86, 88 extend from the edges 73, 74 in a direction generally perpendicular to the general plane of the shells 20, 40.
Each shell 20, 40 may also be provided with tabs or flanges 25, 45. The tabs or flanges 25, 45 extend from a portion of the edges 73, 74 in a direction generally perpendicular to the general plane of the shells 20, 40, but in a direction generally opposite the radial stops or extensions 86, 88. The tabs or flanges 25, 45 help to prevent long-term migration within the disc space, as well as catastrophic posterior expulsion, and the resulting damage to the spinal cord, other nerves, or vascular structures. The tabs or flanges 25, 45 may contain openings 26, 46 that can releasably engage an insertion tool (not shown). The insertion tool will generally contain flexible prongs to releasably engage openings 26, 46. The insertion tool will also generally include a disengagement block that can press against the side of the implant once it has been properly positioned in the intervertebral space and force the openings 26, 46 off of the prongs of the tool.
The shells 20, 40 can be made from any suitable biocompatible rigid material. In accordance with a preferred embodiment, the shells 20, 40 are made from a titanium alloy, and most preferably the titanium alloy is ASTM F-136. The bead coating 22, 42, however, is preferably made from ASTM F-67 pure titanium.
As shown best in FIG. 7, central body 60 is preferably a donut-shaped structure, and includes a convex upper contact surface 94, a convex lower contact surface 96, and a central axial opening 98 formed through an inner surface 67 of the central body. In addition, central body member 60 preferably includes an upper shoulder 92 and a lower shoulder 90. Each shoulder 90, 92 consists of an indentation in the surface of the central body member which defines a ledge that extends around the circumference of the central body 60.”
Among other things, the '787 patent does not teach or suggest the use of doughnut-like implant with an irregular central opening, having a reference central vertical axis, an anterior curvature comprising an aperture located proximate the inferior edge for receiving a fastener, a posterior curvature protruding forward and toward the reference central vertical axis, where the posterior curvature is angled more acutely than the anterior curvature, a first annular-like side distinct from the anterior and posterior curvatures and connected with the anterior solid curvature and the posterior curvature, where the first annular-like side includes an upper boundary and a lower boundary, and where the upper boundary and the lower boundary taper toward each other as the first annular-like side traverses from the anterior curvature to the posterior curvature, a second annular-like side distinct from the anterior and posterior curvatures and connected with the anterior curvature and the posterior curvature, where the second annular-like side includes an upper boundary and a lower boundary, and where the upper boundary and the lower boundary taper toward each other as the second annular-like side traverses from the anterior curvature to the posterior curvature and a plate comprising an aperture, where the plate is connected with the forwardly extending arm, and where the plate extends upward from the forwardly extending arm and is generally parallel the reference axis.
7) US Pub. Patent App. No. 20050240271-Zubok, et al. discloses a cervical disc replacement. Paragraphs 44-46 of Zubok read, “Referring now to FIGS. 1-5, an artificial disc implant 100 of the present invention is shown in perspective, anterior, lateral, lateral cutaway, and posterior cutaway views, respectively. The implant 100 includes a first (e.g., upper) element 200 and a second (e.g., lower) element 300, each having an outwardly facing vertebral body contact surface 202, 302, and each having an inwardly facing articulation surface 204, 304. The elements 200, 300 are disposed as shown with the articulation surfaces 204, 304 nested against one another, and the vertebral body contact surfaces 202, 302 facing away from one another. When the implant 100 is disposed in an intervertebral disc space in a cervical spine, in this configuration and with the vertebral body contact surfaces 202, 302 engaged with respective adjacent vertebral body endplates (not shown), the implant 100 enables the adjacent vertebral bones to move relative to one another in accordance with proper anatomical motion, as further described below.
Preferably, at least one (and more preferably both) of the elements 200, 300 has at least one long-term fixation structure (e.g., flange 206, 306) having at least one feature (e.g., through hole 208 a, 208 b, 308) for securing the element to an adjacent vertebral body. For example, the upper element 200 has an anterior flange 206 that extends upwardly and has two through holes 208 a, 208 b, each of which accepts a bone screw (not shown). And, for example, the lower element 300 has an anterior flange 306 that extends downwardly and has one through hole 308 that accepts a bone screw (not shown). Once the elements 200, 300 are disposed in the intervertebral space with the vertebral body contact surfaces 202, 302 engaged with respective adjacent vertebral body endplates (not shown), securing of bone screws through the holes 208 a, 208 b, 308 and into the anterior surfaces of the adjacent vertebral bones helps prevent the elements from becoming dislodged from, or displaced in, the intervertebral space. Preferably, the bore axes of the through holes 208 a, 208 b, 308 are angled toward the adjacent vertebral body as shown.
Further preferably, at least one (and more preferably both) of the elements 200, 300 has at least one short-term fixation structure (e.g., spike 210 a, 210 b, 310 a, 310 b) for securing the element to an adjacent vertebral body (and more preferably to an adjacent vertebral body endplate). For example, each of the elements 200, 300 has a respective pair of outwardly directed spikes 210 a, 210 b, 310 a, 310 b. Once the elements 200, 300 are disposed in the intervertebral space with the vertebral body contact surfaces 202, 302 engaged with respective adjacent vertebral body endplates (not shown), the spikes 210 a, 210 b, 310 a, 310 b dig into the adjacent vertebral body endplates under the compression along the longitudinal axis of the spinal column, and thus help prevent the elements from becoming dislodged from, or displaced in, the intervertebral space. Preferably, each of the spikes 210 a, 210 b, 310 a, 310 b is sloped toward the vertebral body contact surface 202, 302 and toward the posterior direction on its posterior side as shown, to facilitate ease of insertion of the implant 100 into the intervertebral space, and is either perpendicular to the vertebral body contact surface 202, 302 on its anterior side (as shown) or sloped toward the vertebral body contact surface 202, 302 and toward the posterior direction on its anterior side (not shown), to help prevent the elements 200, 300 from anteriorly (or otherwise) slipping out of the intervertebral space.”
Among other things, the '271 application does not teach or suggest the use of doughnut-like implant with an irregular central opening, having a reference vertical axis, a posterior curvature protruding forward and toward the reference vertical axis, where the posterior curvature is angled more acutely than the anterior curvature, a first annular-like side distinct from the anterior and posterior curvatures and connected with the anterior solid curvature and the posterior curvature, where the first annular-like side includes an upper boundary and a lower boundary, and where the upper boundary and the lower boundary taper toward each other as the first annular-like side traverses from the anterior curvature to the posterior curvature, a second annular-like side distinct from the anterior and posterior curvatures and connected with the anterior curvature and the posterior curvature, where the second annular-like side includes an upper boundary and a lower boundary, and where the upper boundary and the lower boundary taper toward each other as the second annular-like side traverses from the anterior curvature to the posterior curvature and a plate comprising an aperture, where the plate is connected with the forwardly extending arm, and where the plate extends upward from the forwardly extending arm and is generally parallel the reference axis.
8) US Pub. Patent App. No. 20080045952-Kuslich discloses an annulus-reinforcing band. Paragraph 96 of Kuslich reads, “The band 12 is pliable and malleable before its interior space 14 (not shown in FIG. 2) is filled with the contents to be described. While in this initial condition, the band 12 may be passed, in a collapsed state, through a relatively small tube or portal, such as recited in U.S. Pat. Nos. 5,571,189 and 5,549,679, the entire contents of both references being incorporated herein by reference. This feature is important because access to the intervertebral disc is limited by anatomy and therefore safety considerations direct us to use the smallest possible portal of entry.”
Among other things, the '952 application does not teach or suggest the use of doughnut-like implant with an irregular central opening, having a reference vertical axis, a posterior curvature protruding forward and toward the reference vertical axis, where the posterior curvature is angled more acutely than the anterior curvature, a first annular-like side distinct from the anterior and posterior curvatures and connected with the anterior solid curvature and the posterior curvature, where the first annular-like side includes an upper boundary and a lower boundary, and where the upper boundary and the lower boundary taper toward each other as the first annular-like side traverses from the anterior curvature to the posterior curvature, a second annular-like side distinct from the anterior and posterior curvatures and connected with the anterior curvature and the posterior curvature, where the second annular-like side includes an upper boundary and a lower boundary, and where the upper boundary and the lower boundary taper toward each other as the second annular-like side traverses from the anterior curvature to the posterior curvature, a forwardly extending arm attached to the superior edge of the anterior curvature, and a plate comprising an aperture, where the plate is connected with the forwardly extending arm, and where the plate extends upward from the forwardly extending arm and is generally parallel the reference axis.